METHOD OF CULTIVATION OF COAL AND LIGNITE INFIELDS FORMED BY UNCOVERING (OPEN CAST MINING)

Abstract: A method is described to utilize used open-cast lignite mines by installing greenhouses with technological products attaining water economy of 7-8 times, unlimited nutritional capacity by enclosing pesticides and nutrients in a system of resins so as to release elements gradually, and with addition of calcium carbonate so as to limit the creation of sulfiric acid by the action of ground bacteria without pollution of the soil and therefore of need to move the greenhouses. This constitutes an original solution of agricultural utilization of these toxic and infertile soils.

Description: METHOD OF CULTIVATION OF COAL AND LIGNITE INFIELDS FORMED BY UNCOVERING (open cast mining) Inventor: GEORGE VALKANAS 5. The invention describes a method of agricultural utilisation of lignite and coal fields resulting by the technique of uncovering. This method specially describes an original approach of introducing 10. technological products in those fields, which promote water economy, water availability and nutritional efficiency in the soils of lignite and coal fields as they become after the extraction of the carbonaceous matter, introducing agricultural 15. utilisation with massive operation of greenhouses. The lignite and coal fields which result from the technique of uncovering after the extraction of the richer deposits and with the rejected earth stacked 20. in heaps, form surfaces containing carbonous matter which in general are not equilibrated soils and do not show fertility. It also happens that these soil surfaces from recovering and from rejected agregates in heaps, contain also sulfur, usually in high 25. amounts 0,5-3*. Sulfur contained in that soil is converted very rapidly to sulfuric acid through the oxidative action of thiooxidative bacteria which oxidize sulfur. The soils of lignite and coal fields which are formed with the technique of uncovering are considered problematic and toxic and are faced internationally 5. with two technical solutions. a. The solution of covering the fields with fertile top-soil in a depth of 0.8 to 1.20 m which makes a very expensive and laborious approach, which, in spite of these difficulties, is the technical 10. solution in application today. b. The solution of removing the top-soil before the operation of the uncovering technique of the carbonaceous deposit. Top-soil is collected in rolls and is kept in covered shelters until the 15. field deposits are exhausted; then it is placed on the surface of the resulted field. This solution is technically and ecologically correct; however, it is not followed in practice because it is a solution of high sensitivity and of high 20. cost. Thus, the restoration of the soils resulting after mining carbon, lignite or peat deposits is difficult. To improve those to fertile soils is a solution in search since those fields do not improve naturally. 25. These coal or lignite fields apart from the above, face problems because of soil instability and of non retaining water. They are also charged continuously by urban acid precipitates. In case of operation of the thermoelectrical plants for long that charge may result to neutralising all the alkalinity of the soil to form acidic paths or areas. 5. It is estimated that the 60* at least of the sulfur in the carbonaceous matter after burning to produce electricity will precipitate as a gas or in the form of flying ash on the lignite or coal mining area. They make quantities which on operating fields give 10. the following charges (on tons/y) . T A B L E lignite burned flying S02 NOx field lignite ash Megalopol s, 15. Greece 15.000.000 60.000 200.000 150.000 Ptolemais. , Greece 45.000.000 120.000 300.000 500.000 All the above acid precipitates are burdening the ground of the district and neutralize soil alkalinity 20. in a continuous action. But alkalinity is marginal and the final result will be to form acid areas and paths. It is recognized that the sulfur contained in the soil of lignite fields attains high values and with agricultural activity the biological oxidation 25. of sulfur to sulfuric acid will accelerate with destruction of the soil functioning, shown by analysis made in Megalopolis, Greece, lignite field. T A B L E Results from the oxidation of soil samples in the lignite field of Megalopolis, Greece (oxidation of the soil samples with 30* H202) 5. Number of sample pH resulted 1 1.80 2 6.20 3 7.10 10. 4 4.80 5 4.10 6 1.50 7 4.20 8 2.90 15. The agricultural utilization of coal and lignite fields, which are formed with uncovering, is not therefore, feasible today because natural fertility is not available and the solution in use today of fields with soil depth of 0,80-1,20 m. is of high 20. cost and does not offer a possibility, since it is difficult to find much fertile soil to transfer. The operation of thermoelectrical plants on the other hand is to continue with mining coal or l gnite by uncovering the deposits and burning them to produce 25. more and more airborne precipitates. On the other hand it is imperative to create agricultural employemnt for the local population with satisfactory income, and this is only possible through greenhouses, which shall also operate together with the power plants. 5. Supplementary heating with the warm cooling waters which make vast quantities in these areas will be offered, reducing costs. However greenhouses require humus and water retainability. It is experienced 10. that the operation of greenhouses leads to soil contamination and in 2 to 4 years greenhouses need be transferred on new grounds. These conditions, however, cannot prevail in greenhouses operating in coal and lignite fields since they need to be 15. constructed with high technical quality and the transfer shall be very costly. The proposed solution in order to improve those toxic fields and to introduce greenhouse operation is 20. highly original and very profitable. It is a solution based on the above requirements that leads to programmed production, to stable and high water retainability and operate so that nutrition is available according to existing needs biologically 25. controlled, with complete utilization regulated to be slowly consumed so that there is no soil deterioration and materials are not rejected in the environment. The invented solution includes: 5. a) The utilisation of processed polymeric products which in soil retain water in high amounts (200-300 times their weight) . The retained water is quantitatively disposed to serve nutritional needs of the plants since it is molecularly 10. enclosed and does not evaporate neither inf ltrates into the ground. That way water is offered continuously; water economy up to 10 times is achieved. In addition these products advance feeding by ionexchange and absorption - 15. desorption of unlimited capacity; thus they act as fertility promoters which by programming can lead to high quality and quantity in food products, b) The utilization of fertilisers, soil pesticides. 20. and trace metals etc coated in a non-water-soluble form and are bioregradable in soil . Products of the above type a) and b) are in the 25. market today like the polyacry1 mides used as water superabsorbants and coated feeding elements fertilisers, but these are not meeting the above requirements in operating green houses in toxic coal and lignite fields. The above solutions have been studied and realised by the same inventor through the products that the same inventor has developed, viz. the coated fertilisers of trade name Bioval-BRF described in the US Patent 5137 563 and the processed polymers of trade name Hydroval-X described in the relevant Greek patent. 10. The processed polymer products derived mostly from recycled polymers retain water up to 250 times their weight available for plant growth in repeated action to last in soil for many years up to 30 years. The 15. coated fertilisers etc are consumed in soil according to the existing biological activity which is advanced by the action of Hydroval-X. With that pair of technological products continuous 20. nutrition and plant growth in soil is advanced with continuous water offer, water economy and the ability to consume all the nutrients in Bioval-BRF. Therefore no material charges will be created on soil, so as to need replacement. Thus, with this original and highly 25. profitable solution, conditions are formed by which the greenhouse can operate without transposition after 2 to 4 years, which in fact makes a special condition in those fields, where the electricity producing plants still operate and airborne acidic precipitates are produced. However the soil of coal or lignite fields, where the 5. proposed greenhouses are to operate is unstable and contains sulfur. Thus, by introducing plants to grow and biomass production, it will be oxidised to sulfuric acid. Also, in the intensive operation the greenhouses introduce. those events will be 10. accelerated. The invention copes with it as follows: The soil in the greenhouse is mixed with pulverised calcium carbonate in quantity and in depth to create safety in operation without risk for destroying the greenhouse production by acidic contaminates. 15. E X A M P L E 1 The soil where the Greenhouses are to be erected is excavated in depth of 1.5 m, width of 25 m, length of 60 m. The soil of excavation is mixed with 1* to 2* calcium carbonate in pulverised form and the hole 20. formed is filled with soil mixed with calcium carbonate leaving an upper layer of 30 cm. The rest of the excavated soil having calcium carbonate is thoroughly mixed with Hydroval-X I o/oo w/w and with Bioval-BRF 5 o/oo w/w and used to fill up the upper 25. empty part of 30 cm depth. On the conditioned ground a Greenhouse of sofisticated design is then erected having to use heat supplied by the thermoelectrical plants in form of warm cooling water of steam turbines. E X A M P L E 2 Lignite soil of Megalopolis. Greece, which after H202 5. oxidation has shown acidity pH 6,5 is treated according to Example 1 and in a Greenhouse erected on it with heating network supplied by the cooling water supplied by the thermoelectrical plants operating at stable temperature of 30 * C and saturated humidity. 10. The Greenhouse soil is planned and parallel to it a Frame containing not treated lignite soil is placed and in both were planted tomato infant plants with irrigation applied every 3 days. Green House Soil Frame Soil 15. 6 days 15 cm growth 3,8 cm 12 days 20,3 cm growth 7,1 cm 20 days 31 cm growth 10,2 cm 40 days 39 cm growth 12,2 cm 20. tomato plants rich in flowers no flowering occurred dry biomass weight 122gr/plant 32 gr/plant i.e. four times speed and development. E X A M P L E 3 In lignite soil of Ptolemais, Greece, which by 25. oxidation (H202) gave pH 5.8 growth of tomato was organised as in Example 2 The following results were obtained Green House Soil Frame Soil 6 days growth 15 cm 4 cm 12 days growth 22 cm 6 cm 20 days growth 34 cm all plants were destroyed 40 days growth 43 cm tomato plants rich in flowers dry biomass produced 129 g/plant 10, E X A M P L E 4 On Ptolemais lignite soil, which after oxidation (H202) gave pH 6,8 lettuce plants are placed in Greenhouse soil and in Frame the Greenhouse operates at 30 * and is irrigated every 2 days 15, Green House Soil Frame Soil 6 days 16 cm growth 6 cm 12 days 21 cm growth 11.2 cm 20 days 35 cm growth 16 cm 40 days 46 cm growth "20,1 cm 20, dry biomass production 32 gr/plant 10,5 gr/plant E X A M P L E 5 In the greenhouse soil of example 4 the conditions 25. for water economy were studied. After 12 days of growth the plants were left without irrigation. Wilting occurred in 42 days of growth. In between growth was regular without differences to occur. It is thus observed a possibility for water economy up to 7 times not effecting growth. 5.

Claims: C A I M S After the description of the invention and the examples of its experimental realisation, it is 5. claimed: 1. Method of cultivation of lignite and coal fields resulting by uncovering the carbonaceous matter deposits by introducing massive installation of greenhouses operating at 30 * stabely advanced by 10. using also the cooling warm waters of the thermoelectrical plants. 2. Method of cultivation of lignite and coal fields resulted by uncovering the carbonaceous deposits 15. by which is advanced water economy and biologically controlled feeding with protection from sulfur biological oxidation to sulfuric acid by introducing pulverized calcium carbonate 1* to 2* W/W in soil. 20. 3. Method according to claims 1, 2 and 3, by which, in order to promote water economy and biologically controlled feeding, technological products are used, which are multi processed recycled or new polymers, which advance water economy up to 10 times and unlimited feeding efficiency with ionexchange and sorption-desorption. 5. 4. Method according to the claims 1, 2. 3 and 4, by which is advanced fertility efficiency in lignite and coal fields in which the soil acts as support and it is non deteriorated or polluted, so as to 10. be not necessary to move the greenhouse plan. 5. Method according to previous claims by which the greenhouse operation in lignite and coal fields is also supported by utilization of heating using 15. cooling warm waters of the steam turbine of the thermoelectrical plants operating in the field. 6. Method according to claims 1 and 5 by which the lignite and coal fields which result by 20. uncovering the carbonaceous deposits and are non fertile are becoming soils of high fertility that can support the operation of greenhouses with the introduction in those fields protection from biological oxidation of sulfur to sulfuric acid by adding to the soil 1* to 2* calcium carbonate and by adding to the upper layer of the soil technological products advancing water economy and unlimited feeding efficiency and products 5. advancing feeding elements with biologically control, slow release and complete utilisation by which the yield in biomass and in food production are 3 to 5 times higher than usual in greenhouses operation and by which these toxic infertile 10. lignite or coal fields are becoming support for successful operation of greenhouses, which operate with complete pollution control and is non needed to be moved to new grounds.

Inventors: VALKANAS GEORGE N, VALKANAS, GEORGE, N.
Applicants: BIOKAT CORP, VALKANAS GEORGE N, BIOKAT CORPORATION, VALKANAS, GEORGE, N.
Application year: 1994
Main classification: A01G9
IPC codes: A01B79, A01G1, A01G9, C05D3, C05F11, C05G3, E21C41